In engineering education, puzzle solving has long been used to develop critical thinking skills. We here put forward the use of Jigsaw Puzzles in a degree program of electrical engineering for two main purposes: (1) Introduce the concept of complex systems, and (2) Justify the need for a methodological approach in a course of Digital Systems Design. This activity was carried out during the first week of the program course and it has been designed to be conducted in three progressive stages as the level of difficulty in puzzle solving increases. As a preliminary result, we have recognized the high impact in developing communication and teamwork skills, and the need of taking a methodological approach to solve problems.